VideoMark Overlay

A watermark node that has never heard of Wan

Every local video pipeline narrows to the same shape at the end: the model decodes to an IMAGE batch - Wan 2.2, LTX-2, MiniMax H3, Hunyuan, AnimateDiff, indistinguishable from here - and then something turns that batch back into a file. VideoMark Overlay sits in that gap. IMAGE batch in, your text and/or a PNG logo painted onto every frame, IMAGE batch out. No model load, no audio, no file I/O, no idea what generated the frames.

That sounds dull and it's the point. ComfyUI's post-processing options tend to be either "throw another diffusion pass at it" or nothing at all, and a watermark is neither - it's a deterministic pixel op, the kind of job a compositor does perfectly and a sampler only ruins. It also skips the export-review-reimport loop, and single images work unchanged: one photo is a batch of length 1, laid out from its own width and height.

Fair warning: this pack is obscure. Searching the r/StableDiffusion + r/comfyui + r/civitai corpus for "videomark" across two years returns nothing, so there's no adoption story to point you at - and the watermark talk that does exist mostly runs the other way, people removing marks rather than adding them.

How it actually works

The mechanism lives in render.py and it's the right one: at the start of a run the node renders a single RGBA "stamp" at the size of your frames - text, optional logo, stroke and shadow already baked in - then alpha-composites that one sprite onto each frame. Cost per frame is flat, so a 240-frame clip doesn't pay for 240 text renders. It's numpy + Pillow underneath, not torch math: no VRAM cost, nothing to download. Frames are copied before compositing, so upstream tensors aren't mutated.

The number that matters most is scale, the stamp's width as a percentage of frame width rather than pixels. That's why settings tuned at 480p survive a jump to 1440p.

The inputs you'll actually touch

• mode - corner (the default; which corner via position), center, floating, tile. Corner is the answer most of the time: bottom_right unless a platform's like/share buttons live there, in which case top_left.
• text, scale (20% is a sane start for text, 8–18 for a logo), margin (distance from the edge, in pixels - 24–40 for 736×992, 36–64 for 1080p), opacity (0.85 at a corner, and drop to ~0.15 if you go center).
• style - a one-click preset: soft (default), plain, outline, outline_shadow, manual. While a preset is selected the four stroke/shadow controls are ignored entirely, so switch to manual before hand-tuning.
• use_logo is off by default, so a connected logo does nothing until you flip it. The image comes from the optional logo IMAGE input (a wire beats the file) or from logo_file, the input-folder filename the panel's "Upload Logo" button fills in for you.

Optional text_in takes a STRING from any upstream node - Text Concatenate, String Function - and connected, non-empty text overrides the widget. Blank upstream falls back to the widget rather than silently deleting your watermark, which is the sane behaviour when the upstream node returns "".

One output, images: SaveImage for a still, or your video-combine node (VHS Video Combine, Create Video → Save Video) for frames.

Install

# ComfyUI Manager: search "comfyui-videomark"
cd ComfyUI/custom_nodes
git clone https://github.com/kaerozhi/comfyui-videomark.git

Registry route: comfy node install comfyui-videomark. Either way there's no pip step - the pack declares zero dependencies and rides on the torch/numpy/Pillow ComfyUI already ships, which is rare enough in a node pack to be worth saying out loud. Restart afterwards: the visual panel lives in web/, and that directory is only scanned at startup.

Where people get burned

Fonts. 黑体 (simhei) has no © glyph, so a copyright notice renders as boxes; use 微软雅黑 / 宋体 / 楷体, or point font_file at an absolute path. If the dropdown shows only the built-in fallback, font_file is your only route to non-box characters.

Stroke eats your width budget. scale measures the stamp including the stroke, so cranking stroke_width makes the letters smaller. If the mark feels too heavy, lower stroke_opacity first - 1.0 is a solid black ring, 0.5–0.6 a soft edge, 0 is off.

Dark shadow on dark footage is invisible. A black drop shadow on a night shot contributes nothing. Keep the stroke, or set shadow_color light. shadow_offset: 0 turns the shadow into a symmetric halo - lighter to look at, and it doesn't eat into your margin.

On a single photo, start_pct, end_pct, fade_frames and float_cycles do nothing: there's no timeline to walk and no previous frame to fade from. The photo is frame 0, which the default 0→1 window already covers.

Batching mixed photos isn't this node's job. IMAGE is a same-size tensor; 1200×800 and 800×1200 can't share a batch.

Failures pass through silently. If rendering throws, you get your frames back unchanged and one [VideoMark] line in the console. No error - just an unmarked video. The panel also has no live preview by design; you see the result by rendering one.

Editing anything under web/ needs a ComfyUI restart. A JS-only tweak gets away with Ctrl+Shift+R.